This study was carried out to study the combining ability of parental broiler lines using factor analysis of production traits. The single crosses (partial diallel) among the male lines of group 1 (LL, TL, ZL, TT, LT, ZT, ZZ, LZ, and TL) and female lines of group 2 (PP, KP, VP, KK, PK, VK, VV, PV, and KV). A completely randomized blocks design, with three blocks, 81 single crosses and nine females per cross was used. The production traits, were […]

With respect to beef cattle breeding, the emphasis devoted by researchers, beef cattle producers and beef cattle experts has been, in general, focused on identification, evaluation and selection of sires. Little attention has been given to the pathway used to spread the genes from such sires throughout the population as a whole. The reported low annual genetic progress observed in several herds might suggest that, in spite of having some success in promoting genetic improvement as observed in isolated herds, […]

This experiment was carried out to verify the effect of the administration of different doses of GnRH (buserelin) analogue on the emergence of a new follicular growth wave and the number of recruited follicles from this wave, accessory corpus luteum formation, the dominant follicle diameter and the spontaneous corpus luteum on the luteolitic administration day and subsequent synchronization rate and the interval between the PGF2α application and the estrus manifestation. Twenty crossbreed female cattle in diestrus, crossbred Holstein x Zebu […]

The objective of this work was to calculate adjustment factors for milk and fat yield according to the cow age and calving season, for Holstein breeds herds from Minas Gerais State. The statistical analyses were made by means of mixed models, using Restricted Maximum Likelihood in an animal model. The fixed effects were herd-year, genetic composition and age classes-calving season, and as random effects of animal (cow, sire and dam) and error terms. Records used in the analysis were 49,666 […]

The objective of this work was to identify the best semen extender, the dilution rate and the storage time for rooster semen. A total of 60 roosters and 630 hens with 55 weeks of age were artificially inseminated, once a week, by six consecutive weeks, using .05 mL of semen/hen. The treatments were: T1=semen diluted with commercial extender-DC; T2 =semen diluted with Beltsville Poultry Semen Extender-BPSE; T3=semen diluted with Lake solution-LAKE and T4=pure fresh semen (Control). The dilution levels (D) […]

The objective of this experiment was to evaluate the carcass and meat characteristics of Hereford (H), 5/8 H 3/8 Nellore (N), 1/2 H 1/2 N and 1/4 H 3/4 N steers, feedlot finished, from 20 to 24 months of age. Twenty-four steers randomly taken from the same herd were used. The diet contained, in a dry matter basis, 12.7% of crude protein and 57.5:42.5% forage:concentrate ratio. The forage was composed by corn silage + sugar cane (relation 1:1). The slaughter […]

The objective of this work was to estimate the (co) variance components and direct and maternal heritability of the body weights of sheep of Santa Inês breed. A total of 3,771 lambs weights records of the Santa Inês hair sheep breed, progenies of 114 sires, and 758 ewes were analyzed, obtained from experimental herds of EMBRAPA – SNPA from 1985 to 1995. The covariance components and genetic parameters from additive genetic effects, maternal and permanent environmental effects, as well as […]

This study was carried out to analyze the influence of some environmental effects on the milk yield and calving interval and to estimate the genetic parameters at 305-day milk yield (P305), and calving interval (IP). Data from 3044 lactations of 1568 Holstein cows, calved from 1988 to 1995 belonging to dairy herds monitored by DAISY (The Dairy Information System), were used. The Least Squares Method was used to study the environment effects and the Derivative-Free Restricted Maximum Likelihood (REML) algorithm […]

The objetive of this experiment was to obtain data from literature about diet composition for horses and to estimate the digestible energy and digestible protein contents by regression equations from chemical composition of these diets. Data were submitted to a correlation study among the content of nutrients in experimental diets and apparent digestibility coefficients, selecting the best correlation among DE, EAD, OMAD, CPAD and nutrients of diets. The values of EAD, OMAD and CPAD and digestible energy contents were fitted […]

The objective of this work was to determine the digestible (DE) and metabolizable (ME) energy values of some feeds for weaned pigs. Fourteen feeds were evaluated in five experiments, using 144 piglets with an average initial weight of 9.42+0.76 kg at 28 days of age. The DE and ME contents were determined by means of the total collection of feces and urine method. The protein sources from milk had higher energy and protein digestibility than soybean by products. Among these, […]